1. Field of the Invention
The present invention relates to a sealing plate with a filter for a high pressure liquified gas cartridge having a syphon tube.
2. Description of the Prior Art
A cartridge of the type having a double safety device which regulates the quantity of flow of high pressure gas to prevent a cartridge from flying off (like a missile) by reaction and being fixed with a filter on a sealing plate for preventing an orifice from being clogged, has been shown in No. 61-274200 (FIG. 8) and also No. 62-17500 of Japanese Publications, both of which were filed prior to the present application.
A high pressure gas cartridge to which the aforesaid filter is applied, and the cartridge is only charged with a perfectly gasified high pressure gas. Therefore, there are rare cases where cutting dusts and the like remain in a cartridge and moreover, as a flowing substance in the cartridge is a perfectly gasified high pressure gas only, the cutting dusts and the like which are carried by the gas are limited to those which float and slightly stick to the inner wall of the cartridge, and the total quantity thereof is trifling.
On the contrary, in a case of a cartridge to be charged with a liquified gas, the fitted on the portion of a cartridge.
Therefore, by friction between the outer circumferential plane of a syphon tube and the inner wall of a cartridge, micro particles and/or dust are apt to stick to the connecting portion and the like between the outer periphery of the top plane of the syphon tube and the cartridge.
As liquid has a flowing resistance greater than that of gas, when liquid moves in a cartridge, the liquid takes with it these dusts therein. When the liquid flows out of a cartridge, the liquid carries these dusts therewith, and which often causes a clogging of a filter provided on a valve. In such a case, a desired quantity of gas flow becomes unobtainable. Furthermore, in various valve filters, there are those types which are not replaceable or are difficult to replaced, therfore, long and stable use of a filter is most desirable.
It might be thought that it would be good to wash a cartridge after a syphon tube has been utilized, but, in fact, washing a cartridge after the setting of a syphon tube has not been done. That is why, even if a cartridge is washed, when the cartridge is inclined to drain the washing, a large portion of the washings does not flow out and remains in the cartridge, thus the dusts and like cannot be drained.
Accordingly, in a sealing plate and filter combination for a high pressure liquified gas cartridge having a syphon tube, it has been a difficult problem to prevent inner dusts and the like from flowing out.
The present invention solves the problem, by fitting a filter, which is formed like a column or cylinder, having a blind bore which has an opening at one end in the axial direction thereof, onto the main body or sealing plate, by directing said opening of the cylinder to the inner surface of the sealing plate and positively fitting an outer circumferential surface of said filter onto an integral inner circumferential surface of an annulus on the main body or sealing plate.
A sealing plate of the present invention is placed on and over a neck opening of a cartridge with a syphon tube and liquified gas, such as liquified carbon dioxide gas, is charged therein. Then, the sealing plate is welded to the cartridge.
When the cartridge is attached to an opening device and the sealing plate is pierced, the liquified gas flows in the syphon tube, passes through the filter, and flows out of the cartridge. Quantity of flow of the liquified gas is not restrained by the filter. The liquified gas from a valve is supplied to works requiring same, such as washing or cooling of an electronic circuit.
The dust and like particles, which have passed through the syphon tube with the liquified gas, are caught by the filter when they pass therethrough, and only purified gas flows in the valve. Therefore, the, filter, which is provided on the valve, is not clogged in almost all cases, and an expensive valve can be used for long periods of time and is very stable.